Immunogenic compositions and methods of use

ABSTRACT

Disclosed herein are immunogenic compositions comprising a multilayer film comprising two or more layers of polyelectrolytes, wherein adjacent layers comprise oppositely charged polyelectrolytes. A first layer polyelectrolyte comprises an antigenic polypeptide comprising one or more surface adsorption regions covalently linked to one or more antigenic determinant regions, wherein the antigenic polypeptide and the one or more surface adsorption regions have the same polarity. The immunogenic compositions may be employed in methods of eliciting an immune response in a vertebrate organism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.11/586,340 filed Oct. 25, 2006, which claims the benefit of U.S.Provisional Application No. 60/729,828 filed Oct. 25, 2005, which isincorporated by reference herein.

BACKGROUND

Vaccines have been important in medicine ever since it was observedthat, for certain diseases, initial exposure to the infectious agentconferred immunity against subsequent infections. Vaccines have beenused for many years in order to build immunity in an individual againstinfection by particular pathogens such as viruses, bacteria, fungi, andparasites. Vaccines have also been used to stimulate the body's abilityto mount an immune response against antigens on cancer cells, or againstthe formation of pathological fibrils. Vaccines can be administered viavarious routes including, for example, oral, intravenous, subcutaneous,transdermal, sublingual, intramuscular, and nasal administration.

Early vaccines relied on “live” or “killed” pathogens that retainedtheir immunogenicity. A better understanding of the structure andfunction of particular pathogens and of the mechanisms of adaptiveimmunity has made it possible to design safer and more directedvaccines. For example, a current vaccine against the hepatitis B virusrelies on inoculation using only a portion of the viral surface antigen,rather than the complete pathogen. Vaccines of this type have fewerside-effects, and they avoid the unwanted immune responses to antigensthat are non-protective, i.e., do not confer lasting immunity. Vaccineshave also been developed using recombinant DNA technology and genetherapy to provide DNA vaccines, which in favorable cases lead to aprotective immune response.

Vaccination with protein antigens (e.g., from a viral protein or atumor-specific antigen) or immunogenic polypeptides derived from proteinantigens is a new strategy that has tremendous clinical potentialbecause of its low toxicity and widespread applicability. Protein-basedvaccines, however, have had only limited clinical success, due in partto difficulties with delivery. There is therefore a need to develop moreefficacious means of engineering polypeptide-based antigens.

Currently, synthetic peptide vaccines are being evaluated for protectionagainst bacteria, parasites, and viruses. Bacterial epitope vaccinesinclude those directed against cholera and shigella. A synthetic vaccineagainst malaria has undergone Phase I and Phase II clinical trials.Influenza and hepatitis B represent two viral systems in which syntheticpeptide vaccines look especially promising, and there has been muchinterest recently in the development of synthetic vaccines against humanimmunodeficiency virus-1 (HIV-1).

A desirable immune response to a protein or peptide antigen in a vaccinecontext includes both humoral and cellular-mediated immunity. Thehumoral component involves the stimulation of B cells, which produceantibodies, while the cell-mediated component involves T lymphocytes.Cytotoxic T-lymphocytes (CTLs) play an important role in thecell-mediated immune system, lysing virally-infected orbacterially-infected cells. Specifically, CTLs possess cell surfacereceptors, which can recognize foreign peptides associated with MHCclass I and/or class II molecules.

There is a need for methods and specialized delivery platforms suitablefor the delivery of complex antigens such as polypeptides to vertebrateorganisms. The engineering of immunogenic polypeptides and structuresmade of immunogenic polypeptides are promising for this purpose.Preferably, the resulting presentation of immunogenic determinants willactivate at least some components of the adaptive immune system, i.e.,antigen presentation will eliciting a sufficient immune response forcombating a particular pathogen, whether the immune response is mediatedby antibodies, cytotoxic T cells, helper T cells, natural killer cells,or macrophages, or some combination thereof.

SUMMARY

In one embodiment, an immunogenic composition comprises a multilayerfilm comprising two or more layers of polyelectrolytes, wherein adjacentlayers comprise oppositely charged polyelectrolytes, wherein a firstlayer polyelectrolyte comprises an antigenic polypeptide comprising oneor more surface adsorption regions covalently linked to one or moreantigenic determinant regions. The antigenic polypeptide and the one ormore surface adsorption regions have the same polarity. The one or moresurface adsorption regions comprises one or more amino acid sequencemotifs, the one or more amino acid sequence motifs consisting of 5 to 15amino acids and having a magnitude of net charge per residue of greaterthan or equal to 0.4. The one or more antigenic determinant regionscomprise 3 to about 250 amino acid residue. The antigenic polypeptide isnot a homopolymer, is at least 15 amino acids long, and has an aqueoussolubility at pH 4 to 10 of greater than 50 μg/mL. Also, a second layercomprises a second layer polyelectrolyte comprising a polycationicmaterial or a polyanionic material having a molecular weight of greaterthan 1,000 and at least 5 charges per molecule, and a charge oppositethat of the first layer polypeptide.

In another embodiment, a method of eliciting an immune response in avertebrate organism comprises administering into the vertebrate organismthe above-described immunogenic composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of the assembly of oppositely chargedpolypeptides.

FIG. 2 illustrates an embodiment of an antigenic polypeptide comprisingone antigenic determinant region (3) and two surface adsorption regions(1,2), one attached to the N-terminus of the antigenic determinantregion (1) and one attached to the C-terminus of the antigenicdeterminant region (2).

FIG. 3 illustrates independent preparation of the three differentregions of an antigenic polypeptide for LBL by solution-phase synthesis,solid-phase synthesis, or recombinant peptide production.

FIG. 4 illustrates joining of three regions of the antigenic peptide(4).

FIG. 5 illustrates an embodiment of an antigenic polypeptide comprisingtwo surface adsorption regions (120 and 130) and one antigenicdeterminant region (110).

DETAILED DESCRIPTION

The present invention is directed to immunogenic compositions andmethods of eliciting an immune response in a vertebrate organism withthe immunogenic compositions.

As used herein, “layer” means a thickness increment, e.g., on a templatefor film formation, following an adsorption step. “Multilayer” meansmultiple (i.e., two or more) thickness increments. A “polyelectrolytemultilayer film” is a film comprising one or more thickness incrementsof polyelectrolytes. After deposition, the layers of a multilayer filmmay not remain as discrete layers. In fact, it is possible that there issignificant intermingling of species, particularly at the interfaces ofthe thickness increments.

The term “polyelectrolyte” includes polycationic and polyanionicmaterials having a molecular weight of greater than 1,000 and at least 5charges per molecule. Suitable polycationic materials include, forexample, polyamines. Polyamines include, for example, a polypeptide,polyvinyl amine, poly(aminostyrene), poly(aminoacrylate), poly (N-methylaminoacrylate), poly (N-ethylaminoacrylate), poly(N,N-dimethylaminoacrylate), poly(N,N-diethylaminoacrylate), poly(aminomethacrylate),poly(N-methyl amino-methacrylate), poly(N-ethyl aminomethacrylate),poly(N,N-dimethyl aminomethacrylate), poly(N,N-diethylaminomethacrylate), poly(ethyleneimine), poly (diallyl dimethylammoniumchloride), poly(N,N,N-trimethylaminoacrylate chloride),poly(methyacrylamidopropyltrimethyl ammonium chloride), chitosan andcombinations comprising one or more of the foregoing polycationicmaterials. Suitable polyanionic materials include, for example, apolypeptide, a nucleic acid, alginate, carrageenan, furcellaran, pectin,xanthan, hyaluronic acid, heparin, heparan sulfate, chondroitin sulfate,dermatan sulfate, dextran sulfate, poly(meth)acrylic acid, oxidizedcellulose, carboxymethyl cellulose, acidic polysaccharides, andcroscarmelose, synthetic polymers and copolymers containing pendantcarboxyl groups, and combinations comprising one or more of theforegoing polyanionic materials.

“Amino acid” means a building block of a polypeptide. As used herein,“amino acid” includes the 20 common naturally occurring L-amino acids,all other natural amino acids, all non-natural amino acids, and allamino acid mimics, e.g., peptoids.

“Naturally occurring amino acids” means the 20 common naturallyoccurring L-amino acids, that is, glycine, alanine, valine, leucine,isoleucine, serine, threonine, cysteine, methionine, aspartic acid,asparagine, glutamic acid, glutamine, arginine, lysine, histidine,phenylalanine, tyrosine, tryptophan, and proline.

“Non-natural amino acid” means an amino acid other than any of the 20common naturally occurring L-amino acids. A non-natural amino acid canhave either L- or D-stereochemistry.

“Peptoid,” or N-substituted glycine, means an analog of thecorresponding amino acid monomer, with the same side chain as thecorresponding amino acid but with the side chain appended to thenitrogen atom of the amino group rather than to the α-carbons of theresidue. Consequently, the chemical linkages between monomers in apolypeptoid are not peptide bonds, which can be useful for limitingproteolytic digestion.

“Amino acid sequence” and “sequence” mean a contiguous length ofpolypeptide chain that is at least two amino acid residues long.

“Residue” means an amino acid in a polymer or oligomer; it is theresidue of the amino acid monomer from which the polymer was formed.Polypeptide synthesis involves dehydration, that is, a single watermolecule is “lost” on addition of the amino acid to a polypeptide chain.

“Amino acid sequence motif” means a contiguous amino acid sequencecomprising n residues, wherein n is 5 to 15. In one embodiment, themagnitude of the net charge per residue of an amino acid sequence motifis greater than or equal to 0.4. In another embodiment, the magnitude ofthe net charge per residue of an amino acid sequence motif is greaterthan or equal to 0.5. As used herein, the magnitude of the net chargerefers to the absolute value of the net charge, that is, the net chargecan be positive of negative.

As used herein “peptide” and “polypeptide” all refer to a series ofamino acids connected one to the other by peptide bonds between thealpha-amino and alpha-carboxy groups of adjacent amino acids, and maycontain or be free of modifications such as glycosylation, side chainoxidation, or phosphorylation, provided such modifications, or lackthereof, do not destroy immunogenicity. As used herein, the term“peptide” is meant to refer to both a peptide and a polypeptide orprotein.

“Designed polypeptide” means a polypeptide comprising one or more aminoacid sequence motifs, wherein the polypeptide is at least 15 amino acidsin length and the ratio of the number of charged residues of the samepolarity minus the number of residues of the opposite polarity to thetotal number of residues in the polypeptide is greater than or equal to0.4 at pH 7.0. In other words, the magnitude of the net charge perresidue of the polypeptide is greater than or equal to 0.4. In oneembodiment, the ratio of the number of charged residues of the samepolarity minus the number of residues of the opposite polarity to thetotal number of residues in the polypeptide is greater than or equal to0.5 at pH 7.0. In other words, the magnitude of the net charge perresidue of the polypeptide is greater than or equal to 0.5. While thereis no absolute upper limit on the length of the polypeptide, in general,designed polypeptides suitable for ELBL deposition have a practicalupper length limit of 1,000 residues.

“Primary structure” means the contiguous linear sequence of amino acidsin a polypeptide chain, and “secondary structure” means the more or lessregular types of structure in a polypeptide chain stabilized bynon-covalent interactions, usually hydrogen bonds. Examples of secondarystructure include α-helix, β-sheet, and β-turn.

“Polypeptide multilayer film” means a film comprising one or moredesigned polypeptides as defined above. For example, a polypeptidemultilayer film comprises a first layer comprising a designedpolypeptide and a second layer comprising a polyelectrolyte having a netcharge of opposite polarity to the designed polypeptide. For example, ifthe first layer has a net positive charge, the second layer has a netnegative charge; and of the first layer has a net negative charge, thesecond layer has a net positive charge. The second layer comprisesanother designed polypeptide or another polyelectrolyte.

“Substrate” means a solid material with a suitable surface foradsorption of polyelectrolytes from aqueous solution. The surface of asubstrate can have essentially any shape, for example, planar,spherical, rod-shaped, etc. A substrate surface can be regular orirregular. A substrate can be a crystal. A substrate can be a bioactivemolecule. Substrates range in size from the nanoscale to themacro-scale. Moreover, a substrate optionally comprises several smallsub-particles. A substrate can be made of organic material, inorganicmaterial, bioactive material, or a combination thereof. Nonlimitingexamples of substrates include silicon wafers; charged colloidalparticles, e.g., microparticles of CaCO₃ or of melamine formaldehyde;biological cells such as erythrocytes, hepatocytes, bacterial cells, oryeast cells; organic polymer lattices, e.g., polystyrene or styrenecopolymer lattices; liposomes; organelles; and viruses. In oneembodiment, a substrate is a medical device such as an artificialpacemaker, a cochlear implant, or a stent.

When a substrate is disintegrated or otherwise removed during or afterfilm formation, it is called “a template” (for film formation). Templateparticles can be dissolved in appropriate solvents or removed by thermaltreatment. If, for example, partially cross-linked melamine-formaldehydetemplate particles are used, the template can be disintegrated by mildchemical methods, e.g., in DMSO, or by a change in pH value. Afterdissolution of the template particles, hollow multilayer shells remainwhich are composed of alternating polyelectrolyte layers.

A “microcapsule” is a polyelectrolyte film in the form of a hollow shellor a coating surrounding a core. The core comprises a variety ofdifferent encapsulants, for example, a protein, a drug, or a combinationthereof.

“Bioactive molecule” means a molecule, macromolecule, or macromolecularassembly having a biological effect. The specific biological effect canbe measured in a suitable assay and normalizing per unit weight or permolecule of the bioactive molecule. A bioactive molecule can beencapsulated, retained behind, or encapsulated within a polyelectrolytefilm. Nonlimiting examples of a bioactive molecule are a drug, a crystalof a drug, a protein, a functional fragment of a protein, a complex ofproteins, a lipoprotein, an oligopeptide, an oligonucleotide, a nucleicacid, a ribosome, an active therapeutic agent, a phospholipid, apolysaccharide, a lipopolysaccharide. As used herein, “bioactivemolecule” further encompasses biologically active structures, such as,for example, a functional membrane fragment, a membrane structure, avirus, a pathogen, a cell, an aggregate of cells, and an organelle.Examples of a protein that can be encapsulated or retained behind apolypeptide film are hemoglobin; enzymes, such as for example glucoseoxidase, urease, lysozyme and the like; extracellular matrix proteins,for example, fibronectin, laminin, vitronectin and collagen; and anantibody. Examples of a cell that can be encapsulated or retained behinda polyelectrolyte film is a transplanted islet cell, a eukaryotic cell,a bacterial cell, a plant cell, and a yeast cell.

“Biocompatible” means causing no substantial adverse health effect uponoral ingestion, topical application, transdermal application,subcutaneous injection, intramuscular injection, inhalation,implantation, or intravenous injection. For example, biocompatible filmsinclude those that do not cause a substantial immune response when incontact with the immune system of, for example, a human being.

“Immune response” means the response of the cellular or humoral immunesystem to the presence of a substance anywhere in the body. An immuneresponse can be characterized in a number of ways, for example, by anincrease in the bloodstream of the number of antibodies that recognize acertain antigen. Antibodies are proteins secreted by B cells, and anantigen is an entity that elicits an immune response. The human bodyfights infection and inhibits reinfection by increasing the number ofantibodies in the bloodstream and elsewhere.

“Antigen” means a foreign substance that elicits an immune response(e.g., the production of specific antibody molecules) when introducedinto the tissues of a susceptible vertebrate organism. An antigencontains one or more epitopes. The antigen may be a pure substance, amixture of substances (including cells or cell fragments). The termantigen includes a suitable antigenic determinant, auto-antigen,self-antigen, cross-reacting antigen, alloantigen, tolerogen, allergen,hapten, and immunogen, or parts thereof, and combinations thereof, andthese terms are used interchangeably. Antigens are generally of highmolecular weight and commonly are polypeptides. Antigens that elicitstrong immune responses are said to be strongly immunogenic. The site onan antigen to which a complementary antibody may specifically bind iscalled an epitope or antigenic determinant.

“Antigenic” refers to the ability of a composition to give rise toantibodies specific to the composition or to give rise to acell-mediated immune response.

As used herein, the terms “epitope” and “antigenic determinant” are usedinterchangeably and mean the structure or sequence of an antigen, e.g.,a protein or a designed peptide, which is recognized by an antibody.Ordinarily an epitope will be on the surface of a protein. A “continuousepitope” is one that involves several contiguous amino acid residues,not one that involves amino acid residues that happen to be in contactor in the limited region of space in a folded protein. A “conformationalepitope” involves amino acid residues from different portions of thelinear sequence of a protein that come into contact in thethree-dimensional structure of the protein. For efficient interaction tooccur between the antigen and the antibody, the epitope must be readilyavailable for binding. Thus, the epitope or antigenic determinants arepresent in the antigen's native, cellular environment, or only exposedwhen denatured. In their natural form they may be cytoplasmic (soluble),membrane associated, or secreted. The number, location and size of theepitopes will depend on how much of the antigen is presented during theantibody making process.

As used herein, a “vaccine composition” is a composition, which elicitsan immune response in a mammal to which it is administered and whichprotects the immunized organism against subsequent challenge by theimmunizing agent or an immunologically cross-reactive agent. Protectioncan be complete or partial with regard to reduction in symptoms orinfection as compared with a non-vaccinated organism. An immunologicallycross-reactive agent can be, for example, the whole protein (e.g.,glucosyltransferase) from which a subunit peptide has been derived foruse as the immunogen. Alternatively, an immunologically cross-reactiveagent can be a different protein, which is recognized in whole or inpart by antibodies elicited by the immunizing agent.

As used herein, an “immunogenic composition” is intended to encompass acomposition, which elicits an immune response in an organism to which itis administered and which may or may not protect the immunized mammalagainst subsequent challenge with the immunizing agent. In oneembodiment, an immunogenic composition is a vaccine composition.

The present invention is includes both vaccine compositions andimmunogenic compositions comprising a polyelectrolyte multilayer filmcomprising a charged antigenic polypeptide having one or more antigenicdeterminants.

Polyelectrolyte multilayer films are thin films (e.g., a few nanometersto millimeters thick) composed of alternating layers of oppositelycharged polyelectrolytes. Such films can be formed by layer-by-layerassembly on a suitable substrate. In electrostatic layer-by-layerself-assembly (“ELBL”), the physical basis of association ofpolyelectrolytes is electrostatics. Film buildup is possible because thesign of the surface charge density of the film reverses on deposition ofsuccessive layers. The general principle of ELBL deposition ofoppositely charged polyions is illustrated in FIG. 1. The generality andrelative simplicity of the ELBL film process permits the deposition ofmany different types of polyelectrolyte onto many different types ofsurface. Polypeptide multilayer films are a subset of polyelectrolytemultilayer films, comprising at least one layer comprising a chargedpolypeptide. A key advantage of polypeptide multilayer films isenvironmental benignity. ELBL films can also be used for encapsulation.Applications of polypeptide films and microcapsules include, forexample, nano-reactors, biosensors, artificial cells, and drug deliveryvehicles.

The design principles for polypeptides suitable for electrostaticlayer-by-layer deposition are elucidated in U.S. Patent Publication No.2005/0069950, incorporated herein by reference. Briefly, the primarydesign concerns are the length and charge of the polypeptide.Electrostatics is the most important design concern because it is thebasis of ELBL. Without suitable charge properties, a polypeptide willnot be substantially soluble in aqueous solution at pH 4 to 10 andcannot readily be used for the fabrication of a multilayer film by ELBL.Other design concerns include the physical structure of thepolypeptides, the physical stability of the films formed from thepolypeptides, and the biocompatibility and bioactivity of the films andthe constituent polypeptides.

As defined above, a designed polypeptide means a polypeptide comprisingone or more amino acid sequence motifs, wherein the polypeptide is atleast 15 amino acids in length and the magnitude of the net charge perresidue of the polypeptide is greater than or equal to 0.4 at pH 7.0.“Amino acid sequence motif” means a contiguous amino acid sequencecomprising n residues, wherein n is 5 to 15. Positively-charged (basic)naturally-occurring amino acids at pH 7.0 are Arg, His, and Lys.Negatively-charged (acidic) naturally-occurring amino acid residues atpH 7.0 are Glu and Asp. An amino acid motif comprising a mixture ofamino acid residues of opposite charge can be employed so long as theoverall ratio of charge meets the specified criteria. In one embodiment,a designed polypeptide is not a homopolymer.

In one exemplary embodiment, the amino acid sequence motif comprises 7amino acids. Four charged amino acids is a suitable minimum for a motifsize of 7, because fewer than 4 charges yields decreased peptidesolubility and decreased control over ELBL. Further, regardingbiocompatibility, each identified amino acid sequence motif in genomicdata is long enough at 7 residues to constitute a continuous epitope,but not so long as to correspond substantially to residues both on thesurface of a protein and in its interior. Thus, the charge and length ofthe amino acid sequence motif help to ensure that a sequence motifidentified in genomic data is likely to occur on the surface of thefolded protein from which the sequence motif is derived. In contrast, avery short motif could appear to the body to be a random sequence, orone not specifically “self,” and therefore elicit an immune response.

In some cases, a design concern regarding amino acid sequence motifs anddesigned polypeptides is their propensity to form secondary structures,notably α-helix or β-sheet. In some embodiments, it is desirable to beable to control, e.g., minimize, secondary structure formation by thedesigned polypeptides in an aqueous medium in order to maximize controlover thin film layer formation. First, it is preferred that sequencemotifs be relatively short, that is about 5 to about 15 amino acids,because long motifs are more likely to adopt a stable three-dimensionalstructure in solution. Second, a linker, such as a glycine or prolineresidue, covalently joined between successive amino acid sequence motifsin a designed polypeptide will reduce the propensity of the polypeptideto adopt secondary structure in solution. Glycine, for example, has avery low α-helix propensity and a very low β-sheet propensity, making itenergetically very unfavorable for a glycine and its neighboring aminoacids to form regular secondary structure in aqueous solution. Third,the α-helix and β-sheet propensity of the designed polypeptidesthemselves can be minimized by selecting amino acid sequence motifs forwhich the summed α-helix propensity is less than 7.5 and the summedβ-sheet propensity is less than 8. “Summed” propensity means the sum ofthe α-helix or β-sheet propensities of all amino acids in a motif. Aminoacid sequence motifs having a somewhat higher summed α-helix propensityand/or summed β-sheet propensity are suitable for ELBL, particularlywhen joined by linkers such as Gly or Pro. In certain applications, thepropensity of a polypeptide to form secondary structure can berelatively high as a specific design feature of thin film fabrication.The secondary structure propensities for all 20 naturally occurringamino acids can be calculated using the method of Chou and Fasman (seeP. Chou and G. Fasman Biochemistry 13:211 (1974), which is incorporatedby reference herein in its entirety).

Another design concern is control of the stability of polypeptide ELBLfilms. Ionic bonds, hydrogen bonds, van der Waals interactions, andhydrophobic interactions contribute to the stability of multilayerfilms. In addition, covalent disulfide bonds formed betweensulfhydryl-containing amino acids in the polypeptides within the samelayer or in adjacent layers can increase structural strength.Sulfydryl-containing amino acids include cysteine and homocysteine. Inaddition, a sulfhydryl can be added to α-amino acids such asD,L-β-amino-β-cylohexyl propionic acid; D,L-3-aminobutanoic acid; or5-(methylthio)-3-aminopentanoic acid. Sulfhydryl-containing amino acidscan be used to “lock” (bond together) and “unlock” layers of amultilayer polypeptide film by a change in oxidation potential. Also,the incorporation of a sulfhydryl-containing amino acid in a sequencemotif of a designed polypeptide enables the use of relatively shortpeptides in thin film fabrication, by virtue of intermolecular disulfidebond formation. Amino acid sequence motifs containingsulfhydryl-containing amino acids may be selected from a library ofmotifs identified using the methods described below, or designed denovo.

In one embodiment, the designed sulfhydryl-containing polypeptides,whether synthesized chemically or produced in a host organism, areassembled by ELBL in the presence of a reducing agent to preventpremature disulfide bond formation. Following film assembly, thereducing agent is removed and an oxidizing agent is added. In thepresence of the oxidizing agent disulfide bonds form between sulfhydrylsgroups, thereby “locking” together the polypeptides within layers andbetween layers where thiol groups are present. Suitable reducing agentsinclude dithiothreitol (“DTT”), 2-mercaptoethanol (2-ME), reducedglutathione, tris(2-carboxyethyl)phosphine hydrochloride (TCEP), andcombinations of more than one of these chemicals. Suitable oxidizingagents include oxidized glutathione, tert-butylhydroperoxide (t-BHP),thimerosal, diamide, 5,5′-dithio-bis-(2-nitro-benzoic acid) (DTNB),4,4′-dithiodipyridine, sodium bromate, hydrogen peroxide, sodiumtetrathionate, porphyrindin, sodium orthoiodosobenzoate, andcombinations of more than one of these chemicals.

Biocompatibility is a design concern in biomedical applications. In suchapplications, genomic or proteomic information is used as a basis forpolymer design to yield, ideally, “immune inert” polypeptides. Theapproach will be particularly useful if the fabricated or coated objectwill make contact with circulating blood. Because the amino acidsequence motifs are highly polar, they typically occur on the surface ofthe native folded form of the protein from which they are derived. The“surface” is that part of a folded protein that is in contact with thesolvent or inaccessible to the solvent solely because of the granularnature of water. Amino acid sequence motifs identified in blood proteinsare effectively always in contact with cells and molecules of the immunesystem while the protein is in the blood. Therefore, polypeptidesderived from the surface of folded blood proteins are less likely to beimmunogenic than sequences selected at random. Designed polypeptideswill generally be biocompatible, but the extent of immune response orany other type of biological response may well depend on specificdetails of a sequence motif.

Bioactivity can be incorporated into a film, coating or microcapsule bya number of methods. For example, a designed polypeptide comprising thefilm can comprise a functional domain. Alternatively, bioactivity may beassociated with another bioactive molecule encapsulated or coated by thepolypeptide thin film. In one embodiment, the template comprises abioactive molecule such as a protein crystal.

A functional domain in this context is an independently thermostableregion of a protein that has specific biofunctionality (e.g., bindingphosphotyrosine). In a multi-domain protein, multiple functional domainsmay exist, as for example in the protein tensin, which encompasses aphosphotyrosine binding domain and a protein tyrosine phosphatasedomain. The inclusion of a functional domain in a designed polypeptideincorporated into a multilayer film can provide the film with a desiredfunctionality, including, for example, specific ligand binding,targeting in vivo, biosensing, and biocatalysis.

The bioactive molecule can be a protein, a functional fragment of aprotein, a functional fragment of a protein that is not part of adesigned polypeptide, a complex of proteins, an oligopeptide, anoligonucleotide, a nucleic acid, a ribosome, an active therapeuticagent, a phospholipid, a polysaccharide, a lipopolysaccharide, afunctional membrane fragment, a membrane structure, a virus, a pathogen,a cell, an aggregate of cells, an organelle, a lipid, a carbohydrate, apharmaceutical, or an antimicrobial agent. The bioactive molecule can bein the form of a well-ordered or amorphous crystal. The protein can bean enzyme or an antibody. The substrate can comprise the bioactivemolecule. In one embodiment, the substrate has a bioactive moleculedisposed on its surface prior to deposition of layers of oppositelycharged polypeptides. In another embodiment, the substrate is a crystalcomprising the bioactive molecule.

In one embodiment, amino acid sequence motifs are designed de novo. Inother embodiments, amino acid sequence motifs are selected from thegenomic or proteomic information of a specific organism, such as thehuman genome. For example, the primary structure of complement C3(gi|68766) or lactotransferrin (gi|4505043) can be used to search foramino acid sequence motifs in a human blood protein.

A method of identifying a first amino acid sequence motif in apolypeptide comprises selecting a starter amino acid residue in thepolypeptide; examining an amino acid sequence comprising the starteramino acid residue and the following n−1 amino acid residues in thepolypeptide for occurrences of positive and negative charges, wherein nis 5 to 15; determining the 5-15 amino acid residues as an amino acidsequence motif if the net charge of the side chains of the 5-15 aminoacid residues at pH 7 is greater than or equal to 0.4*n; or discardingthe sequence if the net charge of the side chains of the 5-15 amino acidresidues at pH 7 is less than 0.4*n.

In one embodiment, the process of searching protein sequence data for anegatively charged amino acid sequence motif of length n comprising onlyamino acids that are neutral or negatively charged is described asfollows. First, a first amino acid residue is selected in a proteinsequence. Second, this amino acid residue and the following n−1 aminoacid residues are examined for occurrences of arginine (Arg), histidine(His), or lysine (Lys) (the three naturally occurring amino acids thatmay be positively charged at neutral pH), where n is 5 to 15. Third, ifone or more Arg, His, or Lys residues is found in these n amino acidresidues, the process is begun anew at a second amino acid residue. If,however, no Arg, His, or Lys is found in these n residues, the nresidues are examined to determine the number of occurrences ofglutamate (Glu) and/or aspartate (Asp) (the two negatively charged aminoacids at neutral pH). Fourth, if there are at least 0.4*n occurrences ofGlu and/or Asp in the n residues, the sequence is cataloged as anegatively charged amino acid sequence motif. If, however, fewer than0.4*n occurrences of negatively charged amino acids are found, thesequence beginning with the first amino acid residue is discarded andthe process is begun anew, for example, at a second amino acid residueimmediately adjacent to the first amino acid residue. After cataloging amotif, the process can begin anew at a second amino acid residue.

The process for identifying a positively charged sequence motif isanalogous to searching protein sequence data for an n residue-long aminoacid sequence comprising only amino acids that are neutral or positivelycharged, and for which the magnitude of the net charge of the amino acidresidue side chains at neutral pH is greater than or equal to 0.4*n.

Also analogous is the process for identifying a negatively charged aminoacid sequence motif or a positively charged amino acid sequence motif oflength n, allowing both positively and negatively charged amino acidresidues in the motif. For example, the procedure for identifying apositively charged amino acid sequence motif of length n would be toselect a first amino acid residue in a polypeptide. Next, examine thisamino acid residue and the following n−1 amino acids residues foroccurrences of residues that are positively or negatively charged at pH7. Determine the net charge of the n amino acid residue side chains. Ifthe absolute value of the net charge is less than 0.4*n, then thesequence is discarded and a new search is begun at another amino acid,while if the absolute value of the net charge is greater than or equalto 0.4*n, then the sequence is an amino acid sequence motif. The motifwill be positive if net charge is greater than zero and negative if thenet charge is less than zero.

De novo design of amino acid sequence motifs as presently definedfollows essentially similar rules, except that the sequences are notlimited to those found in nature. A length of motif n and a desired signand magnitude of net charge are chosen. Then, n amino acids are selectedfor the amino acid sequence motif that result in the desired sign andmagnitude of charge, so that the absolute value of the net charge of then amino acids is greater than or equal to 0.4*n. A potential advantageof de novo design of an amino acid sequence motif is that thepractitioner can select from among all amino acids (the 20 naturallyoccurring ones and all non-natural amino acids) to achieve the desirednet charge, rather than being limited to the amino acids found in aparticular known protein sequence. The larger pool of amino acidsenlarges the potential range of physical, chemical and/or biologicalcharacteristics that can be selected in designing the sequence of themotif compared to identification of an amino acid sequence motif in agenomic sequence.

A designed polypeptide as presently defined will comprise one or moreamino acid sequence motifs. The same motif may be repeated, or differentmotifs may be joined in designing a polypeptide for ELBL. In oneembodiment, the amino acid sequence motifs are covalently joined with nointervening sequence. In another embodiment, a designed polypeptidecomprises two or more amino acid sequence motifs covalently joined by alinker. The linker can be amino acid based, e.g., one or more amino acidresidues such as glycine or proline, or it can be any other compoundsuitable for covalently linking two amino acid sequence motifs. In oneembodiment, a linker comprises 1-4 amino acid residues, for example, 1-4glycine and/or proline resides. The linker comprises a suitable lengthor composition so that the designed polypeptide is maintained at a netcharge per residue that is greater than or equal to 0.4.

In one embodiment, a designed polypeptide is greater than or equal to 15amino acid residues long. In other embodiments, a designed polypeptideis greater than 18, 20, 25, 30, 32 or 35 amino acids long. 1,000residues is a practical upper bound on polymer length.

Once amino acid sequence motifs have been selected or designed de novo,a designed polypeptide with amino acid-based linkers is synthesizedusing methods well known in the art, such as solid phase synthesis andF-moc chemistry, or heterologous expression in bacteria following genecloning and transformation. Designed polypeptides may be synthesized bya peptide synthesis company, for example, SynPep Corp. (Dublin, Calif.),produced in the laboratory using a peptide synthesizer, or produced byrecombinant DNA methods. Any development of novel methods of peptidesynthesis could enhance the production of peptides but would notfundamentally change peptide design as described herein.

A method of making a designed polypeptide multilayer film comprisesdepositing a plurality of layers of oppositely charged chemical specieson a substrate, wherein at least one layer comprises a designedpolypeptide. Successively deposited polyelectrolytes will have oppositenet charges. FIG. 1 is a schematic illustrating ELBL deposition. In oneembodiment, deposition of a designed polypeptide (or otherpolyelectrolyte) comprises exposing the substrate to an aqueous solutioncomprising a designed polypeptide (or other polyelectrolyte) at a pH atwhich it has a suitable net charge for ELBL. In other embodiments, thedeposition of a designed polypeptide or other polyelectrolyte on thesubstrate is achieved by sequential spraying of solutions of oppositelycharged polypeptides. In yet other embodiments, deposition on thesubstrate is by simultaneous spraying of solutions of oppositely chargedpolyelectrolytes.

In the ELBL method of forming a multilayer film, the opposing charges ofthe adjacent layers provide the driving force for assembly. It is notcritical that polyelectrolytes in opposing layers have the same netlinear charge density, only that opposing layers have opposite charges.One standard film assembly procedure by deposition includes formingaqueous solutions of the polyions at a pH at which they are ionized(i.e., pH 4-10), providing a substrate bearing a surface charge, andalternating immersion of the substrate into the charged polyelectrolytesolutions. The substrate is optionally washed in between deposition ofalternating layer.

The concentration of polyion suitable for deposition of the polyion canreadily be determined by one of ordinary skill in the art. An exemplaryconcentration is 0.1 to 10 mg/mL. Typically, the thickness of the layerproduced is substantially independent of the solution concentration ofthe polyion during deposition in the stated range. For typicalnon-polypeptide polyelectrolytes such as poly(acrylic acid) andpoly(allylamine hydrochloride), typical layer thicknesses are about 3 toabout 5 Å, depending on the ionic strength of solution. Shortpolyelectrolytes typically form thinner layers than longpolyelectrolytes. Regarding film thickness, polyelectrolyte filmthickness depends on humidity as well as the number of layers andcomposition of the film. For example, PLL/PLGA films 50 nm thick shrinkto 1.6 nm upon drying with nitrogen. In general, films of 1 nm to 100 nmor more in thickness can be formed depending on the hydration state ofthe film and the molecular weight of the polyelectrolytes employed inthe assembly.

In addition, the number of layers required to form a stablepolyelectrolyte multilayer film will depend on the polyelectrolytes inthe film. For films comprising only low molecular weight polypeptidelayers, a film will typically have 4 or more bilayers of oppositelycharged polypeptides. For films comprising high molecular weightpolyelectrolytes such as poly(acrylic acid) and poly(allylaminehydrochloride), films comprising a single bilayer of oppositely chargedpolyelectrolyte can be stable.

It is contemplated that an immune response may be elicited viapresentation of any protein or peptide capable of eliciting such aresponse. In one embodiment, the antigen is a key epitope, which givesrise to a strong immune response to a particular agent of infectiousdisease, i.e., an immunodominant epitope. If desired, more than oneantigen or epitope may be included in the immunogenic composition inorder to increase the likelihood of an immune response.

In one embodiment, a multilayer film comprises a first layer antigenicpolypeptide comprising one or more surface adsorption regions covalentlylinked to one or more antigenic determinant regions, wherein the firstlayer antigenic polypeptide and the one or more surface adsorptionregions have the same net polarity. The surface adsorption regionscomprise one or more amino acid sequence motifs. The first layerantigenic polypeptide is at least 15 amino acids long, and has asolubility in aqueous solution at pH 4 to 10 of greater than 50 μg/mL.In one embodiment, the one or more surface adsorption regions and theone or more antigenic determinant regions have the same net polarity. Inanother embodiment, the solubility of the first layer antigenicpolypeptide at pH 4 to 10 is greater than or equal to about 1 mg/mL. Thesolubility is a practical limitation to facilitate deposition of thepolypeptides from aqueous solution. A practical upper limit on thedegree of polymerization of an antigenic polypeptide is about 1,000residues. It is conceivable, however, that longer composite polypeptidescould be realized by an appropriate method of synthesis.

In one embodiment, an antigenic polypeptide comprises a single antigenicdeterminant (3) flanked by two surface adsorption regions, a N-terminalsurface adsorption region (1) and a C-terminal surface adsorption region(2). (FIG. 2)

Each of the independent regions (e.g., antigenic determinant regions (1)and surface adsorption regions (2,3)) of the antigenic polypeptide canbe synthesized separately by solution-phase synthesis, solid-phasesynthesis, or genetic engineering of a suitable host organism. (FIG. 3)Solution-phase synthesis is the method used for production of most ofthe approved peptide pharmaceuticals on the market today. Thesolution-phase method can be used to synthesize relatively long peptidesand even small proteins. The longest peptides that have made by thesolution-phase method are calcitonins (32 mers). More commonly, themethod is used to produce small- or medium-length peptides in quantitiesof up to hundreds of kilograms. It is possible to produce such largequantities of the desired peptides in a facility that follows goodmanufacturing practices.

Alternatively, the various independent regions can be synthesizedtogether as a single polypeptide chain by solution-phase synthesis,solid-phase synthesis, or genetic engineering of a suitable hostorganism. The choice of approach in any particular case will be a matterof convenience or economics.

If the various antigenic determinant regions and surface adsorptionregions are synthesized separately (FIG. 3), once purified, for example,by ion exchange chromatography followed by high-performance liquidchromatography, they are joined by peptide bond synthesis (FIG. 4). Thatis, the N-terminal surface adsorption region (1), the antigenicdeterminant region (3) and the C-terminal antigenic determinant region(2) are covalently joined to produce the antigenic polypeptide (4). Theapproach is similar to so-called hybrid synthesis, wherein peptidesegments with fully protected side chains are synthesized by thesolid-phase technique and then joined by peptide bonds in asolution-phase or solid-phase procedure. This hybrid approach has beenapplied to the synthesis of T20, a 36-amino acid residue peptide, but ithas not been widely exploited.

FIG. 5 illustrates an embodiment of an antigenic polypeptide comprisingtwo surface adsorption regions (120 and 130) and one antigenicdeterminant region (110). 120 is the N-terminal surface absorptionregion. 130 is the C-terminal absorptive region. Each surface adsorptionregion comprises one or more amino acid sequence motifs. An antigenicpolypeptide is a unique combination of surface adsorption region(s) andantigenic determinant region(s) in a single polypeptide chain. Linkerpeptide sequences (140) can be used to generate a composite polypeptidecomprising antigenic determinant regions in a single polypeptide chain.In one embodiment, antigenic determinant region (110) is a smallfunctional region comprising from about 50 to about 130 amino acidresidues, and having a diameter of about 2 nm. In an alternateembodiment, antigenic determinant region (110) is a large functionalregion comprising about 250 amino acid residues, and having a diameterof about 4 nm. The length of 16 amino acid residues in extendedconformation is approximately 5.5 nm.

In one embodiment, an antigenic polypeptide comprises one antigenicdeterminant region and one surface adsorption region, wherein thesurface adsorption region comprises two amino acid sequence motifs. Inanother embodiment, an antigenic polypeptide comprises one antigenicdeterminant region and two surface adsorption regions, one attached tothe N-terminus of the antigenic determinant region and one attached tothe C-terminus of the antigenic determinant region, wherein each surfaceadsorption region comprises one or more amino sequence motifs and thetwo surface adsorption regions are the same or different and have thesame polarity. (FIG. 2) The purpose of the surface adsorption region(s)is to enable adsorption of the polypeptide onto an oppositely chargedsurface in order to build a multilayer film.

The number of surface adsorption regions in an antigenic polypeptiderelative to the number and/or length of the antigenic determinantregions is related to the solubility requirement. For example, if theantigenic determinant region is a short amino acid sequence of, forexample, three amino acid residues, only one amino acid sequence motifof at least 12 amino acid residues will be required to adsorb theantigenic polypeptide onto a suitably charged surface. If, by contrast,the antigenic determinant region is a soluble folded structural domainof a protein comprising, for example, 120 amino acid residues, two aminoacid sequence motifs will typically be sufficient to impart enoughcharge for the antigenic polypeptide to be water soluble and suitablefor adsorption. The motifs could be contiguous and located at theN-terminus of the domain, contiguous and located at the C-terminus ofthe domain, or noncontiguous with one at the N-terminus and one at theC-terminus.

The combined length of the surface adsorption regions is related more tothe dissipation due to thermal energy, which must be overcome forantigenic peptide adsorption to occur spontaneously, than the numberamino acid residues in the antigenic determinant region of the antigenicpolypeptide. Therefore, increasing the degree of polymerization of theantigenic determinant region by a factor of two does not necessarilyrequire surface adsorption regions twice as long for effective bindingof the surface adsorption regions of the antigenic polypeptide. Thephysical basis of adsorption of an antigenic polypeptide to a surface iselectrostatic attraction (and release of counterions to bulk solution),the precise mass of the domain is of secondary importance on the lengthscale of nanometers, and the main “force” counteracting antigenicpolypeptide adsorption is thermal energy. In view of this, one of skillin the art can readily design surface adsorption regions that aresuitable for physical adsorption to a surface of the particularantigenic determinant region of interest.

An antigenic determinant region comprises 3 to about 250 amino acidresidues. The term antigenic determinant region includes both antigenicmotifs and antigenic domains. Antigenic motifs are relatively short andtherefore generally do not have a compact three-dimensional fold;nevertheless, they can exhibit specific antigenicity. While antigenicmotifs generally do not have a compact three-dimensional fold, they cancomprise elements of secondary structure such as α-helices and β-sheets.When the antigenic determinant region is an antigenic motif, it willtypically comprise 3 to about 50 amino acid residues. When the antigenicdeterminant region is an antigenic domain, it will typically compriseabout 50 to about 250 amino acid residues.

An antigenic domain is defined herein as at least a portion of apolypeptide which, when folded, creates its own hydrophobic core. Anative protein, for example, may contain a plurality of structuraldomains, each of which acts as an independent unit of structure andfunction. The biological function of one domain can be completelyindependent of the function of another, as in the case of a catalyticdomain and a binding domain in the same polypeptide chain, where the twodomains do not interact with each other at all. Structural interactionsbetween domains in a native protein are not only possible, butrelatively common; in such cases the interaction between one structuraldomain and another structural domain can be viewed as a type ofquaternary structure.

As used herein, an antigenic domain typically has a minimum of about 50amino acid residues and a maximum of about 250 amino acid residues. Inprinciple, any antigenic domain from a protein can be employed in anantigenic peptide as outlined herein so long as the antigenicpolypeptide has the appropriate aqueous solubility for ELBL deposition.In one embodiment, the antigenic domain has a water solubility at pH 4to 10 of greater than 50 μg/mL. In another embodiment, the antigenicdomain has a water solubility at pH 4 to 10 of greater than or equal to1 mg/mL. In yet another embodiment, the first layer antigenicpolypeptide comprises at least two amino acid sequence motifs when theantigenic determinant region comprises an antigenic domain.

The antigenic polypeptide, when it comprises an antigenic motif insteadof a functional domain, will typically have an magnitude of the netcharge per residue of greater than or equal to 0.4. If, however, theantigenic motif has a net charge per residue of less than 0.4, the oneor more surface adsorption regions will typically have a magnitude ofthe net charge per residue of greater than 0.4 to compensate and givethe antigenic polypeptide the appropriate charge properties forsolubility and physical adsorption.

A polypeptide or antigen may contain one or more distinct antigenicdeterminants. An antigenic determinant may refer to an immunogenicportion of a multichain polypeptide.

The antigenic polypeptide as described herein comprises an antigenicdeterminant region. Suitable antigenic determinant regions include viralantigens, bacterial antigens, fungal antigens, parasite antigens, tumorantigens, antigens involved in autoimmunity, and combinations comprisingone or more of the foregoing antigenic determinant regions.

In one embodiment, the antigenic determinant region comprises a viralantigen. Suitable viral antigens include, but are not limited to,retroviral antigens such as HIV-1 antigens including the gene productsof the gag, pol, and env genes, the Nef protein, reverse transcriptase,and other HIV components; hepatitis viral antigens such as the S, M, andL proteins of hepatitis B virus, the pre-S antigen of hepatitis B virus,and other hepatitis, e.g., hepatitis A, B, and C, viral components;influenza viral antigens such as hemagglutinin and neuraminidase andother influenza viral components; measles viral antigens such as themeasles virus fusion protein and other measles virus components; rubellaviral antigens such as proteins E1 and E2 and other rubella viruscomponents; rotaviral antigens such as VP7sc and other rotaviralcomponents; cytomegaloviral antigens such as envelope glycoprotein B andother cytomegaloviral antigen components; respiratory syncytial viralantigens such as the M2 protein and other respiratory syncytial viralantigen components; herpes simplex viral antigens such as immediateearly proteins, glycoprotein D, and other herpes simplex viral antigencomponents; varicella zoster viral antigens such as gpI, gpII, and othervaricella zoster viral antigen components; Japanese encephalitis viralantigens such as proteins E, M-E, M-E-NS 1, NS 1, NS 1-NS2A, 80% E, andother Japanese encephalitis viral antigen components; rabies viralantigens such as rabies glycoprotein, rabies nucleoprotein and otherrabies viral antigen components; and combinations comprising one or moreof the foregoing antigenic determinant regions.

In another embodiment, the antigenic determinant region comprises abacterial antigen. Suitable bacterial antigens include, but are notlimited to, pertussis bacterial antigens such as pertussis toxin,filamentous hemagglutinin, pertactin, FIM2, FIM3, adenylate cyclase andother pertussis bacterial antigen components; diptheria bacterialantigens such as diptheria toxin or toxoid and other diptheria bacterialantigen components; tetanus bacterial antigens such as tetanus toxin ortoxoid and other tetanus bacterial antigen components; streptococcalbacterial antigens such as M proteins and other streptococcal bacterialantigen components; gram-negative bacilli bacterial antigens;Mycobacterium tuberculosis bacterial antigens such as heat shock protein65 (HSP65), the 30 kDa major secreted protein, antigen 85A and othermycobacterial antigen components; Helicobacter pylori bacterial antigencomponents; pneumococcal bacterial antigens such as pneumolysin, andother pneumococcal bacterial antigen components; haemophilus influenzabacterial antigens; anthrax bacterial antigens such as anthraxprotective antigen and other anthrax bacterial antigen components;rickettsiae bacterial antigens such as romps and other rickettsiaebacterial antigen components; and combinations comprising one or more ofthe foregoing antigenic determinant regions.

In another embodiment, the antigenic determinant region comprises afungal antigen. Suitable fungal antigens include, but are not limitedto, candida fungal antigen components; histoplasma fungal antigens suchas heat shock protein 60 (HSP60) and other histoplasma fungal antigencomponents; cryptococcal fungal antigens such as capsularpolysaccharides and other cryptococcal fungal antigen components;coccidiodes fungal antigens such as spherule antigens and othercoccidiodes fungal antigen components, and tinea fungal antigens such astrichophytin and other coccidiodes fungal antigen components; andcombinations comprising one or more of the foregoing antigenicdeterminant regions.

In another embodiment, the antigenic determinant region comprises aparasite antigen. Suitable protozoal and other parasitic antigensinclude, but are not limited to, plasmodium falciparum antigens such asmerozoite surface antigens, sporozoite surface antigens,circumsporozoite antigens, gametocyte/gamete surface antigens,blood-stage antigen pf 1 55/RESA and other plasmodial antigencomponents; toxoplasma antigens such as SAG-1, p30 and other toxoplasmaantigen components; schistosomae antigens such asglutathione-S-transferase, paramyosin, and other schistosomal antigencomponents; leishmania major and other leishmaniae antigens such asgp63, lipophosphoglycan and its associated protein and other leishmanialantigen components; and trypanosoma cruzi antigens such as the 75-77 kDaantigen, the 56 kDa antigen and other trypanosomal antigen components;and combinations comprising one or more of the foregoing parasiteantigens.

In one embodiment, the antigenic determinant region comprises a tumorantigen. Suitable tumor antigens include, but are not limited to,prostate specific antigen (PSA), telomerase; multidrug resistanceproteins such as P-glycoprotein; MAGE-1, alpha fetoprotein,carcinoembryonic antigen, mutant p53, papillomavirus antigens,gangliosides or other carbohydrate-containing components of melanoma orother tumor cells; and combinations comprising one or more of theforegoing tumor antigens. It is contemplated that antigens from any typeof tumor cell can be used in the compositions and methods describedherein.

In another embodiment, the antigenic determinant region comprises anantigen involved in autoimmunity. Suitable antigens which have beenshown to be involved in autoimmunity include, but are not limited to,myelin basic protein, myelin oligodendrocyte glycoprotein andproteolipid protein of multiple sclerosis and CII collagen protein ofrheumatoid arthritis; and combinations comprising one or more of theforegoing antigenic determinant regions.

Knowledge of antigenic determinants or epitopes for antigens of thepathogen of the target disease can be a useful starting point for thedevelopment of synthetic peptide vaccines. The more that is known abouta pathogen, its mechanisms of action, and how the immune system respondsto infection, the better the odds of preparing a successful vaccine.Complete determination of the structure of the genome of a pathogen is aroutine and rapid procedure which can aid in the determination ofantigenic determinant sites for know pathogens.

Methods and techniques for determining the location and composition ofan antigenic determinant or epitope for a specific antibody are wellknown in the art. These techniques can be used to identify and/orcharacterize epitopes for use as antigenic determinant regions. In oneembodiment, mapping/characterization methods of an epitope for anantigen specific antibody can be determined by epitope “foot-printing”using chemical modification of the exposed amines/carboxyls in theantigenic protein. One example of such a foot-printing technique is theuse of HXMS (hydrogen-deuterium exchange detected by mass spectrometry)wherein a hydrogen/deuterium exchange of receptor and ligand proteinamide protons, binding, and back exchange occurs, wherein the backboneamide groups participating in protein binding are protected from backexchange and therefore will remain deuterated. Relevant regions may beidentified at this point by peptic proteolysis, fast microborehigh-performance liquid chromatography separation, and/or electrosprayionization mass spectrometry.

In another embodiment, a suitable epitope identification technique isnuclear magnetic resonance epitope mapping (NMR), where typically theposition of the signals in two-dimensional NMR spectra of the freeantigen and the antigen complexed with the antigen binding peptide, suchas an antibody, are compared. The antigen typically is selectivelyisotopically labeled with 15N so that only signals corresponding to theantigen and no signals from the antigen binding peptide are seen in theNMR-spectrum. Antigen signals originating from amino acids involved inthe interaction with the antigen binding peptide typically will shiftposition in the spectra of the complex compared to the spectra of thefree antigen, and the amino acids involved in the binding may beidentified that way.

In another embodiment, epitope mapping/characterization may be done bypeptide scanning. In this approach, a series of overlapping peptidesspanning the full-length of the polypeptide chain of an antigen areprepared and tested individually with regard to immunogenicity. Theantibody titer of the corresponding peptide antigen is determined by astandard method, e.g., enzyme-linked immunosorbent assay. The variouspeptides can then be ranked with regard to immunogenicity, providing anempirical basis for selection of peptide design for vaccine development.

In another embodiment, protease digestion techniques may also be usefulin the context of epitope mapping and identification. Antigenicdeterminant-relevant regions/sequences may be determined by proteasedigestion, e.g. by using trypsin in a ratio of about 1:50 to antigenicprotein overnight (0/N) digestion at 37° C. and pH 7-8, followed by massspectrometry (MS) analysis for peptide identification. The peptidesprotected from trypsin cleavage by the antigenic protein maysubsequently be identified by comparison of samples subjected to trypsindigestion and samples incubated with CD38BP and then subjected todigestion by e.g. trypsin (thereby revealing a foot print for thebinder). Other enzymes like chymotrypsin, pepsin, etc. may also oralternatively be used in a similar epitope characterization method.Moreover, protease digestion can provide a quick method for determiningthe location of a potential antigenic determinant sequence within aknown antigenic protein using a known antibody.

The invention is further directed to an immunogenic composition, saidimmunogenic composition comprising a multilayer film comprising two ormore layers of polyelectrolytes, wherein adjacent layers compriseoppositely charged polyelectrolytes, wherein a first layerpolyelectrolyte comprises an antigenic polypeptide. The immunogeniccomposition optionally further comprises one or more layers comprisingadditional antigenic polypeptides.

In one embodiment, an immunogenic composition comprises a plurality ofantigenic determinant regions, either on the same or different antigenicpolypeptides. The plurality of antigenic determinants may be from thesame or different infectious agents. In one embodiment, the immunogeniccomposition comprises a plurality of unique antigenic polypeptides. Inanother embodiment, the immunogenic composition comprises a plurality ofimmunogenic peptides comprising multiple antigenic determinant regionswithin each polypeptide. In another embodiment, the polypeptide is aconjugated peptide comprising an antigenic peptide mixture conjugated toa lipid moiety, or conjugated to a carrier protein moiety. An advantageof these immunogenic compositions is that multiple antigenicdeterminants or multiple conformations of a single linear antigenicdeterminant can be present in a single synthetic vaccine particle. Suchcompositions with multiple antigenic determinants can potentially yieldantibodies against multiple epitopes, increasing the odds that at leastsome of the antibodies generated by the immune system of the organismwill neutralize the pathogen or target specific antigens on cancercells, for example.

In one embodiment, the immunogenic composition comprises a plurality ofantigenic polypeptides, wherein each of the antigenic polypeptides is animmunogen of the same pathogen. Optionally, the immunogenic compositionincludes a plurality of antigenic polypeptides directed to differentepitopes of the same pathogen. The different epitopes are optionallyfound in regions in close proximity on the pathogen surface. Thus, inone embodiment, the first layer polyelectrolyte comprises two or moreantigenic determinants. In another embodiment, the multilayer filmcomprises a second antigenic polypeptide comprising one or more secondsurface adsorption regions covalently linked to one or more secondantigenic determinant regions, wherein the second antigenic polypeptideand the one or more second surface adsorption regions have the samepolarity, wherein the one or more second surface adsorption regionscomprises one or more second amino acid sequence motifs, the one or moresecond amino acid sequence motifs consisting of 5 to 15 amino acids andhaving a magnitude of net charge per residue of greater than or equal to0.4, and wherein the one or more second antigenic determinant regionscomprises 3 to about 250 amino acid residues, wherein the secondantigenic polypeptide is not a homopolymer, is at least 15 amino acidslong, and has an aqueous solubility at pH 4 to 10 of greater than 50μg/ml.

The immunogenicity of an immunogenic composition may be enhanced in anumber of ways. In one embodiment, the multilayer film optionallycomprises one or more additional immunogenic bioactive molecules.Although not necessary, the one or more additional immunogenic bioactivemolecules will typically comprise one or more additional antigenicdeterminants. Suitable additional immunogenic bioactive moleculesinclude, for example, a drug, a protein, an oligonucleotide, a nucleicacid, a lipid, a phospholipid, a carbohydrate, a polysaccharide, alipopolysaccharide, or a combination comprising one or more of theforegoing bioactive molecules. Other types of additional immuneenhancers include a functional membrane fragment, a membrane structure,a virus, a pathogen, a cell, an aggregate of cells, an organelle, or acombination comprising one or more of the foregoing bioactivestructures.

In one embodiment, the multilayer film optionally comprises one or moreadditional bioactive molecules. The one or more additional bioactivemolecule can be a drug. Alternatively, the immunogenic composition is inthe form of a hollow shell or a coating surrounding a core. The corecomprises a variety of different encapsulants, for example, one or moreadditional bioactive molecules, including, for example, a drug. Thus,the immunogenic compositions designed as described herein could also beused for combined therapy, e.g., eliciting an immune response and fortargeted drug delivery. Micron-sized “cores” of a suitable therapeuticmaterial in “crystalline” form can be encapsulated by immunogeniccomposition comprising the antigenic polypeptides, and the resultingmicrocapsules could be used for drug delivery. The core may be insolubleunder some conditions, for instance high pH or low temperature, andsoluble under the conditions where controlled release will occur. Thesurface charge on the crystals can be determined by ζ-potentialmeasurements (used to determine the charge in electrostatic units oncolloidal particles in a liquid medium). The rate at which microcapsulecontents are released from the interior of the microcapsule to thesurrounding environment will depend on a number of factors, includingthe thickness of the encapsulating shell, the antigenic polypeptidesused in the shell, the presence of disulfide bonds, the extent ofcross-linking of peptides, temperature, ionic strength, and the methodused to assemble the peptides. Generally, the thicker the capsule, thelonger the release time.

In another embodiment, the additional immunogenic biomolecule is anucleic acid sequence capable of directing host organism synthesis of adesired immunogen or interfering with the expression of geneticinformation from a pathogen. In the former case, such a nucleic acidsequence is, for example, inserted into a suitable expression vector bymethods known to those skilled in the art. Expression vectors suitablefor producing high efficiency gene transfer in vivo include retroviral,adenoviral and vaccinia viral vectors. Operational elements of suchexpression vectors include at least one promoter, at least one operator,at least one leader sequence, at least one terminator codon, and anyother DNA sequences necessary or preferred for appropriate transcriptionand subsequent translation of the vector nucleic acid. In particular, itis contemplated that such vectors will contain at least one origin ofreplication recognized by the host organism along with at least oneselectable marker and at least one promoter sequence capable ofinitiating transcription of the nucleic acid sequence. In the lattercase, multiple copies of such a nucleic acid sequence will be preparedfor delivery, for example, by encapsulation of the nucleic acids withina polypeptide multilayer film in the form of a capsule for intravenousdelivery.

In construction of a recombinant expression vector, it shouldadditionally be noted that multiple copies of the nucleic acid sequenceof interest (either E1 or core) and its attendant operational elementsmay be inserted into each vector. In such an embodiment, the hostorganism would produce greater amounts per vector of the desired E1 orcore protein. The number of multiple copies of the nucleic acid sequencewhich may be inserted into the vector is limited only by the ability ofthe resultant vector due to its size, to be transferred into andreplicated and transcribed in an appropriate host microorganism.

In a further embodiment, the immunogenic composition comprises a mixtureof antigenic peptides/immunogenic bioactive molecules. These may bederived from the same antigen, they may be different antigens from thesame infectious agent or disease, or they may be from differentinfectious agents or diseases. The complex or mixture will thereforeraise an immune response against a number of antigens and possibly anumber of infectious agents or diseases as specified by the antigenicpeptide/protein components of the delivery system.

In one embodiment, the immunogenic composition evokes a response fromthe immune system to a pathogen. In one embodiment, a vaccinecomposition comprises an immunogenic composition in combination with apharmaceutically acceptable carrier. Thus a method of vaccinationagainst a pathogenic disease comprises the administering to a subject inneed of vaccination an effective amount of the immunogenic composition.

Pharmaceutically acceptable carriers include, but are not limited to,large, slowly metabolized macromolecules such as proteins,polysaccharides, polylactic acids, polyglycolic acids, polymeric aminoacids, amino acid copolymers, inactive virus particles, and the like.Pharmaceutically acceptable salts can also be used in the composition,for example, mineral salts such as hydrochlorides, hydrobromides,phosphates, or sulfates, as well as the salts of organic acids such asacetates, proprionates, malonates, or benzoates. The composition canalso contain liquids, such as water, saline, glycerol, and ethanol, aswell as substances such as wetting agents, emulsifying agents, or pHbuffering agents. Liposomes can also be used as carriers.

A method of eliciting an immune response against a disease or pathogenin a vertebrate (e.g., vaccination) comprises administering animmunogenic composition comprising a multilayer film comprising anantigenic polypeptide. In one embodiment, the antigenic polypeptide isin the most exterior or solvent-exposed layer of the multilayer film.The immunogenic composition can be administered orally, intranasally,intravenously, intramuscularly, subcutaneously, intraperitoneally,sublingually, or transdermally, either with or without a booster dose.Generally, the compositions are administered in a manner compatible withthe dosage formulation, and in such amount as will be prophylacticallyand/or therapeutically effective. Precise amounts of immunogeniccomposition to be administered depend on the judgment of thepractitioner and may be peculiar to each subject. It will be apparent tothose of skill in the art that the therapeutically effective amount ofan immunogenic composition will depend, inter alia, upon theadministration schedule, the unit dose of antigen administered, whetherthe compositions are administered in combination with other therapeuticagents, and the immune status and health of the recipient. Atherapeutically effective dosage can be determined by the ordinaryskilled medical worker based on patient characteristics (age, weight,sex, condition, complications, other diseases, etc.), as is well knownin the art. Furthermore, as further routine studies are conducted, morespecific information will emerge regarding appropriate dosage levels fortreatment of various conditions in various patients, and the ordinaryskilled worker, considering the therapeutic context, age and generalhealth of the recipient, is able to ascertain proper dosing.

The immunogenic composition optionally comprises an adjuvant. Adjuvantsin general comprise substances that boost the immune response of thehost in a non-specific manner. Selection of an adjuvant depends on thesubject to be vaccinated. Preferably, a pharmaceutically acceptableadjuvant is used. For example, a vaccine for a human should avoid oil orhydrocarbon emulsion adjuvants, including complete and incompleteFreund's adjuvant. One example of an adjuvant suitable for use withhumans is alum (alumina gel). A vaccine for an animal, however, maycontain adjuvants not appropriate for use with humans.

The invention is further illustrated by the following nonlimitingexamples.

EXAMPLES Example 1 Vaccine Composition for HIV-1 with a Single AntigenicDeterminant

The antigenic polypeptide comprises a single antigenic determinantregion, wherein the antigenic determinant region is a polypeptidesequence from a pathogen and the surface adsorption region is located atthe N-terminus of the antigenic determinant region. In one example, theantigenic determinant region is an antigenic determinant in a knownpathogen, e.g., HIV-1, e.g., peptide ARP7022, orDQQLLGIWGCSGKLICTTAVPWNC (SEQ ID NO: 1). A suitable antigenicpolypeptide comprises:

(SEQ ID NO: 2) KKKAKKKGKKKAKKKGDQQLLGIWGCSGKLICTTAVPWNC

The surface adsorption region of the antigenic peptide comprisesKKKAKKKGKKKAKKKG (SEQ ID NO: 3). The 24-residue ARP7022 sequence (SEQ IDNO. 1) represents a conserved immunodominant region of HIV-1glycoprotein 41 (residues 593-616) and is recognized by most Europeanand African HIV+ sera (Lange et al. (1993) AIDS 7, 461). The full-lengthpeptide corresponding to SEQ ID NO. 2 is synthesized by one of any meansknown in the art. Artificial viruses are prepared with this peptide anumber of ways, e.g., by depositing by LBL immunogenic compositionscomprising 5 bilayers of poly(L-lysine) and poly(L-glutamic acid) and afinal layer of the peptide corresponding to SEQ ID NO. 2 onto 3-μmdiameter microparticles of calcium carbonate. The artificial virusesprepared in this way have an exterior or surface exposed layer which isformed of multiple copies of the immunogenic peptide represented by SEQID NO. 2. The polypeptide concentration for adsorption of each layer is2 mg-mL⁻¹ in an aqueous solution at pH 7. The adsorption time for eachlayer is 20 min. Microparticles are “rinsed” between each peptideadsorption step by centrifugation. In some cases, the calcium carbonatetemplate particles of the final artificial virus construct are dissolvedby treatment with EDTA. The structures thus prepared can be referred toas artificial viruses or synthetic vaccines: They “display” on theirsurface antigenic determinants, in the present case multiple copies ofan antigenic determinant known to elicit an immune response thatgenerates antibodies which recognize intact HIV-1. The technology ispromising for preventative medicine and HIV-1 treatment.

Example 2 Vaccine Composition for HIV-1 with Multiple AntigenicDeterminants

There are two main types of immunogenic compositions with multipleantigenic determinants: 1) Each antigenic polypeptide adsorbedsimultaneously comprises an identical plurality of antigenic determinantregions, wherein the antigenic determinant regions of the polypeptideare the same or different and the antigenic determinant regions arebased on the same or a different pathogen, and 2) Multiple antigenicpeptides adsorbed simultaneously each comprise one of a plurality offunctional units, wherein the functional regions are or are not based onthe same pathogen. It is important to mention that mixed solutions ofthe two types of peptide are, in principle, no less useful forfabrication of the surface layer of an artificial virus than solutionsof one indicated type or the other. The surface adsorption regions ofeither type will ordinarily but need not be identical from peptide topeptide. Moreover, the surface adsorption regions can be located at theN-terminus of the composite antigenic peptide, at the C-terminus,between functional regions in the same composite peptide, or somecombination of these possibilities.

Type 1 immunogenic composition with multiple antigenic determinants. Inthis example, the antigenic polypeptide comprises two antigenicsequences in the antigenic determinant region, wherein both of theantigenic sequences are from a the same pathogen and there are surfaceadsorption regions located at the N-terminus of the antigenicdeterminant region, at the C-terminus of the antigenic determinantregion, and between the antigenic sequences. In one example, theantigenic determinants are from a known pathogen, e.g., HIV-1, e.g.,peptide ARP7022, or DQQLLGIWGCSGKLICTTAVPWNC (SEQ ID NO: 1), andLQARILAVERYLKDQQL (SEQ ID NO:4). A suitable antigenic polypeptidecomprises:

(SEQ ID NO: 5) KKKAKKKGKKKAKKKGDQQLLGIWGCSGKLICTTAVPWNCGKKKAKKKGKKKAKKKGLQARILAVERYLKDQQLKKKAKKKGKKKAKKKG

The surface adsorption regions of the composite antigenic peptidecomprise KKKAKKKGKKKAKKKG (SEQ ID NO: 3). SEQ ID NO. 4 corresponds toresidues 67-83 of HIV-1 glycoprotein 41. As before, the full-lengthpeptide corresponding to SEQ ID NO. 5 is synthesized by one of any meansknown in the art. Artificial viruses are prepared with this peptide anumber of ways, e.g., by depositing by LBL immunogenic compositionscomprising 5 bilayers of poly(L-lysine) and poly(L-glutamic acid) and afinal layer of the peptide corresponding to SEQ ID NO. 5 onto 3-μmdiameter microparticles of calcium carbonate. The artificial virusesprepared in this way have an exterior or surface exposed layer which isformed of multiple copies of the immunogenic peptide represented by SEQID NO. 5. The polypeptide concentration for adsorption of each layer is2 mg-mL⁻¹ in an aqueous solution at pH 7. The adsorption time for eachlayer is 20 min. Microparticles are “rinsed” between each peptideadsorption step by centrifugation. In some cases, the calcium carbonatetemplate particles of the final artificial virus construct are dissolvedby treatment with EDTA. The structures thus prepared can be referred toas artificial viruses or synthetic vaccines: They “display” on theirsurface antigenic determinants, in the present case multiple copies ofan antigenic determinant known to elicit an immune response thatgenerates antibodies which recognize intact HIV-1. The technology ispromising not only for preventative medicine and for HIV-1 therapy, butalso cancer therapy (when the antigenic sequences represent cancer cellsurface markers).

Example 3 Immunogenic Composition for HIV-1 and SARS

The antigenic polypeptide comprises two antigenic determinant regionsand two surface adsorption regions, wherein the antigenic determinantregions are polypeptide sequences from a single pathogen and the surfaceadsorption regions are located at the N-terminus and C-terminus of theantigenic polypeptide and the first antigenic determinant region isseparated from the central surface adsorption region a short linker. Inone example, one antigenic determinant region is a known antigenicdeterminant in a pathogen, e.g., HIV-1, e.g., peptide ARP7022, orDQQLLGIWGCSGKLICTTAVPWNC (SEQ ID NO: 1), and the other antigenicdeterminaqt region, viz., YSRVKNLNSSEG (SEQ ID NO:6), is from a putativeenvelope protein from severe acute respiratory syndrome (SARS) virus,and the short linker is a single glycine residue, G:

(SEQ ID NO: 7) KKKAKKKGKKKAKKKGDQQLLGIWGCSGKLICTTAVPWNCGKKKAKKKGKKKAKKKGYSRVKNLNSSEGKKKAKKKGKKKAKKKGAs before, the surface adsorption regions of the composite antigenicpeptide each comprise KKKAKKKGKKKAKKKG (SEQ ID NO: 3).

Example 4 Vaccine Composition for a Fungus with a Single AntigenicDeterminant

The antigenic polypeptide comprises a single antigenic determinantregion, wherein the antigenic determinant region is a polypeptidesequence from a pathogen and the surface adsorption region is located atthe C-terminus of the antigenic determinant region. In one example, theantigenic determinant region is a signal sequence in a protein, e.g.,Ag2/PRA, of a pathogen, e.g., Coccidioides immitis, e.g.,MQFSHALIALVAAGLASA (SEQ ID NO: 8). A suitable antigenic polypeptidecomprises:

MQFSHALIALVAAGLASAKKKAKKKGKKKAKKKG (SEQ ID NO: 9)

The surface adsorption region of the antigenic peptide comprisesKKKAKKKGKKKAKKKG (SEQ ID NO: 3). The 18-residue sequence from Ag2/PRA(SEQ ID NO. 8) represents a region of Coccidioides immitis, thecausative agent of coccidioidomycosis (San Joaquin Valley fever), arespiratory disease. The full-length peptide corresponding to SEQ ID NO.9 is synthesized by one of any means known in the art. Multilayer filmsare prepared with this peptide a number of ways, e.g., by depositing byLBL immunogenic compositions comprising 5 bilayers of poly(L-lysine) andpoly(L-glutamic acid) and a final layer of the peptide corresponding toSEQ ID NO. 9 onto 3-μm diameter microparticles of calcium carbonate. Thefilms prepared in this way have an exterior or surface exposed layerwhich is formed of multiple copies of the immunogenic peptiderepresented by SEQ ID NO. 9. The polypeptide concentration foradsorption of each layer is 2 mg-mL in an aqueous solution at pH 7. Theadsorption time for each layer is 20 min. Microparticles are “rinsed”between each peptide adsorption step by centrifugation. In some cases,the calcium carbonate template particles of the final artificial virusconstruct are dissolved by treatment with EDTA. The structures thusprepared can be referred to as artificial viruses or synthetic vaccines:They “display” on their surface antigenic determinants, in the presentcase multiple copies of an antigenic determinant known to elicit animmune response that generates antibodies which recognize intactCoccidioides immitis. The technology is promising for preventativemedicine and Coccidioides immitis treatment.

Example 5 Vaccine Composition for a Bacterium with Multiple AntigenicDeterminants

The antigenic polypeptide comprises a single antigenic determinantregion, wherein the antigenic determinant region comprises twopolypeptide sequences from a pathogenic bacterium and the surfaceadsorption regions are located at the C-terminus of the antigenicdeterminant region, at the N-terminus of the antigen determinant region,and between the two sequences from the pathogenic bacterium. In oneexample, the antigenic determinants are from a protein, e.g., thesurface protein antigen PAc from Streptococcus mutans MT8148, e.g.,NAKATYEAALKQYEADLAAVKKANAA (SEQ ID NO: 10) and AALTAENTAIKQRNENAKA (SEQID NO: 11). A suitable antigenic polypeptide comprises:

(SEQ ID NO: 12) KKKAKKKGKKKAKKKGNAKATYEAALKQYEADLAAVKKANAAGAALTAENTAIKQRNENAKAGKKKAKKKGKKKAKKKG

The surface adsorption regions of the antigenic peptide compriseKKKAKKKGKKKAKKKG (SEQ ID NO: 3). The sequences from the PAc gene product(SEQ ID NO. 10 and SEQ ID NO. 11) represent a portion of thealanine-rich repeating region in the surface protein antigen, which hasreceived much attention as an antigenic component for vaccines againstdental caries. The full-length peptide corresponding to SEQ ID NO. 12 issynthesized by one of any means known in the art. Multilayer films areprepared with this peptide a number of ways, e.g., by depositing by LBLimmunogenic compositions comprising 5 bilayers of poly(L-lysine) andpoly(L-glutamic acid) and a final layer of the peptide corresponding toSEQ ID NO. 12 onto 3-μm diameter microparticles of calcium carbonate.The films prepared in this way have an exterior or surface exposed layerwhich is formed of multiple copies of the immunogenic peptiderepresented by SEQ ID NO. 12. The polypeptide concentration foradsorption of each layer is 2 mg-mL⁻¹ in an aqueous solution at pH 7.The adsorption time for each layer is 20 min. Microparticles are“rinsed” between each peptide adsorption step by centrifugation. In somecases, the calcium carbonate template particles of the final artificialvirus construct are dissolved by treatment with EDTA. The structuresthus prepared can be referred to as artificial viruses or syntheticvaccines: They “display” on their surface antigenic determinants, in thepresent case multiple copies of an antigenic determinant known to elicitan immune response that generates antibodies which recognize intact S.mutans. The technology is promising for preventative medicine and S.mutans treatment.

In summary, the artificial viruses fabricated with immunogenic peptidesby ELBL demonstrate the following advantages. Synthetic peptide vaccineseliminate the need for certain vaccine safety tests, reducing the costand risk of vaccine production. For example, the specific toxicity testis used to detect incomplete inactivation of virions for vaccinesinvolving attenuated or killed virus particles, for example, by cellculture analysis, saving time and resources. A vaccine construct thatdoes not use a virus or other type of pathogen as the immunogeneliminates the need for such safety tests. In addition, since mammaliancell culture is not needed to propagate viruses for the invention, therisk of contamination of the present vaccine with unwanted material froma virus, microorganism, or eukaryote is extremely low, particularly ifthe synthetic peptides and artificial viruses are produced under GMPconditions.

Additional advantages of the presently claimed invention includesimplicity of fabrication and rapid response by virtue of the “cassette”approach to synthesis of peptides suitable for LBL.

Moreover, the approach enables multiple conformations of a single linearantigenic determinant to be “displayed” simultaneously on the surface ofsingle synthetic vaccine particle, yielding antibodies against multipleconformations of the sequence and thereby increasing the odds that atleast some of the antibodies generated by the immune system of theorganism will neutralize the pathogen or target specific antigens oncancer cells. As stated above, it is envisioned that peptides containingdifferent functional regions could be incorporated into a singlesynthetic vaccine construct, increasing the spectrum of protection: Thepresently claimed synthetic vaccine can present multiple antigenicdeterminants directed to multiple pathogens, providing protectionagainst many different pathogens in a single vaccination.

The synthetic vaccine platform is extremely general and, in principle,can work for any pathogen. Thus, unlike other known vaccinationapproaches, which require engineering of genes, transfer of the genes toa suitable expression host, expression of the genes, purification of therecombinant protein or virus particles, etc., the synthetic vaccinesdisclosed herein can provide for a decreased response time to the threatof a pathogen.

The use of the terms “a” and “an” and “the” and similar referents(especially in the context of the following claims) are to be construedto cover both the singular and the plural, unless otherwise indicatedherein or clearly contradicted by context. The terms first, second etc.as used herein are not meant to denote any particular ordering, butsimply for convenience to denote a plurality of, for example, layers.The terms “comprising”, “having”, “including”, and “containing” are tobe construed as open-ended terms (i.e., meaning “including, but notlimited to”) unless otherwise noted. Recitation of ranges of values aremerely intended to serve as a shorthand method of referring individuallyto each separate value falling within the range, unless otherwiseindicated herein, and each separate value is incorporated into thespecification as if it were individually recited herein. The endpointsof all ranges are included within the range and independentlycombinable. All methods described herein can be performed in a suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”), is intended merely to better illustrate theinvention and does not pose a limitation on the scope of the inventionunless otherwise claimed. No language in the specification should beconstrued as indicating any non-claimed element as essential to thepractice of the invention as used herein.

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims. Any combination of the above-described elements in all possiblevariations thereof is encompassed by the invention unless otherwiseindicated herein or otherwise clearly contradicted by context.

1. A multilayer film comprising two or more layers of polyelectrolytes,wherein adjacent layers comprise oppositely charged polyelectrolytes,wherein a first layer polyelectrolye comprises a first antigenicpolypeptide comprising one or more surface adsorption regions covalentlylinked to one or more antigenic determinant regions, wherein the firstantigenic polypeptide and the one or more surface adsorption regionshave the same polarity, wherein the one or more surface adsorptionregions comprises one or more amino acid sequence motifs, the one ormore amino acid sequence motifs consisting of 5 to 15 amino acidresidues and having a magnitude of net charge per residue of greaterthan or equal to 0.4, and wherein the one or more antigenic determinantregions comprises 3 to about 250 amino acid residues, and one or moreantigenic determinant regions comprises an antigen from a parasite,wherein the first antigenic polypeptide is an unbranched polypeptide, isnot a homopolymer, is at least 15 amino acid residues long, and has anaqueous solubility at pH 4 to 10 of greater than 50 μg/ml; wherein asecond layer comprises a second layer polyelectrolyte comprising apolycationic material or a polyanionic material having a molecularweight of greater than 1,000 and at least 5 charges per molecule, and acharge opposite that of the first layer polypeptide.
 2. The multilayerfilm of claim 1, wherein the first antigenic polypeptide is in theexterior layer of the multilayer film.
 3. The multilayer film of claim1, wherein the first antigenic polypeptide comprises two or moreantigenic determinants.
 4. The multilayer film of claim 3, wherein thetwo or more antigenic determinants are from the same or differentpathogen or target disease.
 5. The multilayer film of claim 1, furthercomprising a second antigenic polypeptide comprising one or more secondsurface adsorption regions covalently linked to one or more secondantigenic determinant regions, wherein the second antigenic polypeptideand the one or more second surface adsorption regions have the samepolarity, wherein the one or more second surface adsorption regionscomprises one or more second amino acid sequence motifs, the one or moresecond amino acid sequence motifs consisting of 5 to 15 amino acids andhaving a magnitude of net charge per residue of greater than or equal to0.4, and wherein the one or more second antigenic determinant regionscomprises 3 to about 250 amino acid residues, wherein the secondantigenic polypeptide is not a homopolymer, is at least 15 amino acidslong, and has an aqueous solubility at pH 4 to 10 of greater than 50μg/ml.
 6. The multilayer film of claim 5, wherein the one or more firstantigenic determinant regions and the one or more second antigenicdeterminant regions are from the same or different parasite.
 7. Themultilayer film of claim 1, further comprising a drug, anoligonucleotide, a nucleic acid, a lipid, a phospholipid, acarbohydrate, a polysaccharide, a lipopolysaccharide, or a combinationof one or more of the foregoing molecules.
 8. The multilayer film ofclaim 1, wherein the antigenic polypeptide has an aqueous solubility ofgreater than or equal to about 1 mg/mL.
 9. The multilayer film of claim1, wherein the one or more antigenic determinant regions comprises anantigenic motif comprising 3 to about 50 amino acid residues, andwherein the first antigenic polypeptide has a magnitude of charge perresidue at neutral pH of greater than or equal to 0.4.
 10. Themultilayer film of claim 1, wherein the one or more antigenicdeterminant regions is an antigenic domain comprising about 50 to about250 amino acid residues.
 11. The multilayer film of claim 10, whereinthe antigenic domain has a water solubility at pH 4 to 10 of greaterthan 50 μg/mL.
 12. The multilayer film of claim 1, wherein themultilayer film encapsulates one or more non-peptide molecules.
 13. Themultilayer film of claim 1, wherein the multilayer film is in the formof a microcapsule.
 14. The multilayer film of claim 13, wherein themicrocapsule comprises a core comprising a drug, a protein, anoligonucleotide, a nucleic acid, a lipid, a phospholipid, acarbohydrate, a polysaccharide, a lipopolysaccharide, or a combinationof one or more of the foregoing molecules.
 15. The multilayer film ofclaim 1, wherein the antigen is selected from the group consisting of aplasmodia antigen, a toxoplasma antigen, a schistosomae antigen, aleishmania antigen, and a trypanosoma cruzi antigen.
 16. The multilayerfilm of claim 1, wherein the antigen is a plasmodium falciparum antigen.17. A method of eliciting an immune response in a vertebrate organismcomprising administering into the vertebrate organism a compositioncomprising, a multilayer film comprising two or more layers ofpolyelectrolytes, wherein adjacent layers comprise oppositely chargedpolyelectrolytes, wherein a first layer polyelectrolye comprises a firstantigenic polypeptide comprising one or more surface adsorption regionscovalently linked to one or more antigenic determinant regions, whereinthe antigenic polypeptide and the one or more surface adsorption regionshave the same polarity, wherein the one or more surface adsorptionregions comprises one or more amino acid sequence motifs, the one ormore amino acid sequence motifs consisting of 5 to 15 amino acids andhaving a magnitude of net charge per residue of greater than or equal to0.4, and wherein the one or more antigenic determinant regions comprises3 to about 250 amino acid residues, and one or more antigenicdeterminant regions comprises an antigen from a parasite, wherein theantigenic polypeptide is an unbranched polypeptide, is not ahomopolymer, is at least 15 amino acid residues long, and has an aqueoussolubility at pH 4 to 10 of greater than 50 μg/ml; wherein a secondlayer comprises a second layer polyelectrolyte comprising a polycationicmaterial or a polyanionic material having a molecular weight of greaterthan 1,000 and at least 5 charges per molecule, and a charge oppositethat of the first layer polypeptide.
 18. The method of claim 17, whereinthe multilayer film is administered intramuscularly or subcutaneously.19. A method of making a multilayer film, the method comprising:depositing a first layer polyelectrolyte on a surface of a substrate toform a first layer; wherein, the first layer polyelectrolye comprises afirst antigenic polypeptide comprising one or more surface adsorptionregions covalently linked to one or more antigenic determinant regions,wherein the first antigenic polypeptide and the one or more surfaceadsorption regions have the same polarity, wherein the one or moresurface adsorption regions comprises one or more amino acid sequencemotifs, the one or more amino acid sequence motifs consisting of 5 to 15amino acids and having a magnitude of net charge per residue of greaterthan or equal to 0.4, and wherein the one or more antigenic determinantregions comprises 3 to about 250 amino acid residues, and one or moreantigenic determinant regions comprises an antigen from a parasite,wherein the first antigenic polypeptide is an unbranched polypeptide, isnot a homopolymer, is at least 15 amino acid residues long, and has anaqueous solubility at pH 4 to 10 of greater than 50 μg/ml; depositing asecond layer polyelectrolyte on the first layer polyelectrolyte to forma second layer; wherein a second layer comprises a second layerpolyelectrolyte comprising a polycationic material or a polyanionicmaterial having a molecular weight of greater than 1,000 and at least 5charges per molecule, and a charge opposite that of the first layerpolypeptide.